Heat Flow Determinations Research Articles

HEAT FLOW DETERMINATIONS IN THE CANADIAN ARCTIC ARCHIPELAGO

Three heat flow determinations a were made in M'Clure Strait between Prince Patrick and Banks Islands in the northwestern part of the Arctic Archipelago of Canada. The three stations lie within 55 km of a point some 130 km SSW. of Mould Bay, Prince Patrick Island, and yield a weighted mean heat flow of 0.84 ± 0.09 μcal cm−2 s−1, or 57% only of the worldwide continental average. The measurements were made from sea ice in water depths of some 430 m using a thermal probe and portable equipment carried in a fixed-wing aircraft.Instrumental limitations and errors are discussed, together with environmental factors. The uncertainties in interpreting this result as a truly subnormal equilibrium heat flow are outlined but it is concluded that the calculated systematic errors are unlikely to exceed 25%. Consequently in the absence of any known major perturbing effect, it must be concluded that the structure responsible for the suppression of vertical magnetic held variations at Mould Bay observatory does not extend 130 km to the south, is not produced by an anomalously high near-surface temperature, or is of late-Quaternary origin.

Heat flow in oligocene sediments at Szentendre

In an exploration borehole of 500 m depth at Szentendre detailed geothermal measurements were made for the determination of the terrestrial heat flow. The hole crossed porous Oligocene sandstone containing clay minerals. 40 rock samples were collected but the cores lost a considerable part of their pore-water while taking ont of the borehole and transporting into the laboratory. Resaturation was not possible owing to desintegration of the samples due to swelling of clay minerals. The author presents a method for overcoming this difficulty. It there exist a suitable model of pore distribution, the approximatein situ conductivity can be established. At first the rock specimen is completely dired out and the dry conductivity is measured. Then the specimen is saturated with some organic liquid or mineral oil with known conductivity and the conductivity is measured again. From these two values and from the conductivities of the air and liquid, with help of the pore structure model, thein situ conductivity can be approximated. After comparing his results to other investigators experiments, the heat flow is computed using the method described for the determination of thein situ conductivity. The heat flow amounts to $$2.01 \cdot 10^{ - 6} cal/cm^2 ,\sec $$ which is consistent to other results in the Hungarian basin.

Anisotropic thermal conductivity

The direct determination of thermal conductivity in situ is desirable for the accurate determination of the geothermal heat flow. If the material is thermally isotropic, the method of using a point source of heat and measuring the gradient at some distance away leads to a determination of the conductivity. However, difficulties are encountered if the medium is thermally anisotropic. The problem is particularly acute for a rather thick layer which has different conductivities in different directions; such common rocks as shales, slates, and some sandstones exhibit directional conductivity.

An experimental study of critical heat loads at boiling of organic liquids on a submerged heating surface

Data of experiments for the determination of critical heat flows at boiling of methyl alcohol ( P = 1–64.5 atm) and normal propyl alcohol ( P = 1–46 atm) on a submerged heating surface are deduced in the present paper. The treatment of experiments is given in relative co-ordinates. The influence of different factors on the values of critical flows is shown.

THE PRESENT STATE OF GEOTHERMAL INVESTIGATIONS

At present, the emphasis in geothermal studies in non‐volcanic areas is on the flow of heat to the surface, a quantity of much theoretical importance. The number of reliable determinations of heat flow is still small, with few of the oil‐producing regions represented. While thermal gradients range from about 5 to 70°C/km, most of the measurements of heat flow fall within the range [Formula: see text], including the recent values for the deep ocean basins. There are suggestions of regional variations, but many more measurements reliable to 10% or better will be needed for further progress. The study of regions or provinces, rather than single localities, is especially desirable, and should be feasible in areas extensively drilled for oil. The principal requirements, which are difficult to meet, are: 1) approximate thermal equilibrium, which may require an undisturbed period of many months, and 2) availability for laboratory study of cores representing the major formations penetrated by the well. A renewal of interest in this subject among oil geologists, with recognition and exploitation of opportunities as they arise, could greatly advance its development.

The Present State of Geothermal Investigations

At present, the emphasis in geothermal studies in non‐volcanic areas is on the flow of heat to the surface, a quantity of much theoretical importance. The number of reliable determinations of heat flow is still small, with few of the oil‐producing regions represented. While thermal gradients range from about 5 to 70°C/km, most of the measurements of heat flow fall within the range 1.2⋅10-6cal/cm2‐sec±50%, including the recent values for the deep ocean basins. There are suggestions of regional variations, but many more measurements reliable to 10% or better will be needed for further progress. The study of regions or provinces, rather than single localities, is especially desirable, and should be feasible in areas extensively drilled for oil. The principal requirements, which are difficult to meet, are: 1) approximate thermal equilibrium, which may require an undisturbed period of many months, and 2) availability for laboratory study of cores representing the major formations penetrated by the well. A rene...

TERRESTRIAL HEAT FLOW IN PERSIA

Summary Measurements are described which permit the determination of the terrestrial heat flow in eighteen bore holes in S.W. Persia. The variations of heat flow that are found to exist can to a large extent be explained by the geological structure. The influence of topographic irregularities, climatic changes, recent tectonic movements and denudation upon the heat flow is discussed. If we assume that the climate has become warmer in the last 10,000 years this may have reduced the terrestrial heat flow by at most 0.31×10−6 cal./cm.2 sec. The other agencies discussed have only a small influence upon the observed heat flow. The mean value of the heat flow in eighteen bore holes is 0.87×10−6 cal./cm.2 sec. This is a low value, but it agrees rather well with the recently determined values of 0.98×10−6 in Great Britain and 1.16×10−6 in South Africa.